1. Field of the Invention
This invention relates to ski boot bindings for touring skis.
2. Prior Art
Ski touring, or cross-country skiing, involves travelling on snow using very light weight, narrow skis. Suitable terrain for this type of skiing is less steep than most alpine, or downhill ski courses, and involves climbing, walking on level terrain and, inevitably, skiing down moderate slopes. Touring or cross-country skis, ski boots and ski bindings are markedly different from alpine or downhill skis, ski boots and ski bindings. Touring skis are long, narrow and light in weight and are fairly fragile. Alpine skis are considerably shorter and wider and are much heavier and stronger. Touring ski boots are comfortable and light weight with soft flexible uppers and flexible soles that are normally attached to the ski at the toe end only. Alpine ski boots are heavy rigid affairs with thick inflexible soles that are attached to the skis at both front and rear ends. Touring skis bindings normally secure the toe only of the ski boot to the ski, and these toe bindings do not have a safety release feature and must be released by hand. Alpine ski bindings have built-in safety release features which automatically release the ski boot in the event of an accident while skiing.
As noted, touring skis are of very light construction, usually of either laminated wood or fiberglass, and touring boots are light weight and low cut and have a very flexible sole to allow the boot heel to be raised freely while walking or gliding on the skis. Conventional touring ski boot bindings (of which there are several well known types) are of light weight construction in keeping with the need to minimize the weight of touring ski equipment. Due to the light weight of touring ski equipment and the generally low speeds and straight running of the touring skier, forces at the ski boot binding are small and no safety-release capability is required. Nonetheless, the ski boot binding should be capable of maintaining the toe of the ski boot securely fastened to the ski, while permitting the ski boot to flex freely and preventing as far as possible lateral motion of the boot relative to the ski when the skier is walking on his skis.
There are two main types of touring ski boot bindings commonly available to the touring skier -- namely, the cable type and the pin type binding. Cable bindings employ a toe piece that is secured to the upper surface of the touring ski and that is adapted or shaped to receive the toe of a touring ski boot thrust thereinto. The toe piece has vertical wings which extend rearwardly alongside the front part of the ski boot to help align the ski boot on the ski. A cable attached either to the ski in front of the toe piece or to the toe piece itself extends around the heel of the ski boot to hold the boot in the toe piece. Pin bindings also employ a toe piece that is secured to the ski and that is shaped much like the toe piece of the cable binding. The toe piece of the pin binding is provided with vertical pins (usually 3) which fit into corresponding holes formed in the sole of the ski boot at the toe of the boot. A clamp pivotally mounted on the toe piece overlies the outer edges of the sole of the ski boot at the toe end thereof and securely clamps the toe of the boot on to the pins of the toe piece when the toe of the ski boot is in the toe piece and the clamp is at its secured position.
Neither the cable binding nor the pin binding provides an entirely satisfactory solution to the problem of securing the toe of the touring ski boot to a touring ski in that both types permit excessive lateral motion of the ski boot relative to the ski when the skier is walking. This excessive lateral motion of the ski boot is tiring and reduces control of the skis. In addition, the flared vertical wings of the toe piece project laterally outwardly from both sides of each touring ski and have a tendency to damage the other ski in the event the skis should run together.
After an intensive investigation into the problem of providing a satisfactory toe binding for touring skis, we have now devised an improved touring ski toe binding which is light in weight and reliable in operation, and which substantially eliminates lateral motion of the ski boot relative to the ski when the skier is walking without the requirement for any part of the toe binding to extend laterally outwardly beyond the side edges of the ski or ski boot.